NO. 9 OLFACTORY SENSE OF INSECTS — MclXDOO 47 



the surrounding,- cliitin, hut only stains less decplv. In a typical 

 olfactory pore the neck (NklH) of the flask is wide and the mouth 

 ( MF) is tfarint;-. The sense fiher ( SF) of the sense cell ( SC) pierces 

 the hottoni of the cone and enters the round, ohlonj^-. or slitlike pore 

 aperture ( I'orAp). The nerve hher (NF) soon runs to a nerve. It 

 is thus seen that the cytoplasm (Cyt) in the peripheral end of the 

 sense fiber comes in direct contact with the air containin,!:;- odorous 

 particles and that odors do not have to pass throui^h a hard membrane 

 in order to stimulate the sense cells as is claimed for the antennal 

 organs. 



To determine the function of these pores the wings, legs and stings 

 of many worker honey bees were mutilated. The behavior of the 

 mutilated bees was carefully studied, and they were tested with odors 



\Con ^Z' 



ChL- 



V\Q. 6. — Cross section of a typical olfactory pore with its sense cell (5^0 

 from the tibia of the hind leg of a worker bee, x 700. 



in the same manner as were unmutilated ones. The stings of lOO 

 workers were pulled out. These bees lived 30 hours on an average. 

 Twenty of them were tested with odors. They responded only 

 slightly more slowly than unmutilated bees. The wings of 28 work- 

 ers were pulled ofT. When tested with odors, these bees responded 

 one-eighth as rapidly as norinal bees. The bases of the wings of 20 

 workers were covered with liquid glue. When tested, these bees 

 responded also one-eighth as rapidly as unmutilated ones. The pores 

 on the legs of 20 workers were covered with a mixture of beeswax 

 and vaseline. When tested, these bees responded two-fifths as 

 rapidly as unmutilated workers. The wings were pulled ofif and the 

 pores on the legs of 20 workers were covered with the beeswax- 

 vaseline mixture. When tested with odors, these workers responded 

 one-twelfth as rapidly as unmutilated workers. All of the workers 

 with mutilated wings and legs lived just as long in the observation 

 cases as did unmutilated workers, and they were absolutely normal 



